The young mathematical disciple '' might be of some help in making psychology a real science. - Kurt Zadek Lewin

An attempt to improve intergroup relations has to face a wide variety of tasks. It deals with problems of attitude and stereotypes in regard to other groups and to one's own group, with problems of development of attitudes and conduct during childhood and adolescence, with problems of housing, and the change of the legal structure of the community; it deals with problems of status and caste, with problems of economic discrimination, with political leadership and with leadership in many aspects of community life. It deals with the small social body of a family, a club or a friendship group, with the larger social body of a school or a school system, with neighborhoods and with social bodies of the size of a community, of the state, a nation and with international problems.

Theoretical psychology in its present state must try to develop a system of concepts which shows all the characteristics of a Gestalt, in which any part depends upon every other part. As we do not yet have the knowledge of facts which really suffices to determine this system of concepts and as, on the other hand, this knowledge of "facts" cannot be acquired without developing this system of concepts, there seems to be only one way open: to proceed slowly by tentative steps, to make decisions rather reluctantly, to keep in view always the whole field of psychology, and to stay in closest contact with the actual work of psychological research.

Working in this field I felt that I had begun a task methodologically and technically sound and necessary, the broader elaboration of which could not be expected for decades. Nevertheless it soon became clear that though these problems are difficult, they are by no means impossible to solve. One had only to clear out a number of hoary philosophical prejudices and to set his scientific goal high enough to arrive at explanation and prediction. Today it can no longer be doubted that the questions set, for example, by psychoanalysis are readily accessible to experimental clarification if only appropriate methods and concepts are employed.